Preliminary Studies on Metabolic Effects of a Continuous-Dose , Progestogen-Only , Oral Contraceptive

Abstract

A continuous daily dose of 0-3 mg norethisterone acetate was administered as contraceptive to 321 women for a total of 1857 cycles. The method had a failure rate equivalent to nine pregnancies per 100 women-year of use. Cycles during treatment were irregular, but otherwise few side-effects were reported. The preparation had small, but probably significant effects on urinary steroid excretions, and from pregnanediol estimations it seemed likely that ovulation was inhibited in some patients. Most other biochemical parameters examined on blood and urine samples were little altered, but serum iron and iron-binding capacity were significantly elevated